This invention relates to the art of containerized transportation of bulk or manufactured cargo wherein efficient loading and unloading, as well as effective protection, of the cargo being handled is essential.
A primary asset of containerization of cargos is resulting facilitation in cargo handling. Containers are thus utilized interchangeably for land and ocean transportation and, on land, by rail or truck. Containers generally are of standard modular dimensions and cargos of high and low density alike are frequently containerized in the same sized full height dry freight container irrespective of the nature of the commodity or the economic justification. In certain trading patterns, low package density cargo is frequently predominant in one direction whereas high package density cargo comprises the majority of volume in the other or opposite direction. Sometimes containers move whereby they are filled in one direction and returned in an empty condition. Thus the over-standardization of cargo containers has led, at least in part, to a lack of their adaptability for various trade conditions and routes. As the following described prior art will indicate, these problems have been long known in the industry and the approach to solution is generally directed to providing containers in sections which nest together for empty return--usually for specialized one-way cargos only--and to containers which are expansible by one means or another.